JPS58136781A - Composition and method for treating metal surface coated with phosphate - Google Patents

Abstract

The invention relates to a composition and a process for the treatment, more precisely the "post-treatment" of phosphatized metal surfaces, particularly when the surfaces must be subsequently covered with a coat of paint. It relates also to a process for the preparation of the composition and a concentrate useful for this preparation. The composition comprises an effective proportion of trivalent titanium compound and it is presented with an acid pH, the proportion of said compound being sufficient for the corresponding composition to confer on the treated metal surface a protection equivalent to that obtained with known chromatizing solutions. More particularly, the composition contains trivalent titanium at a concentration of 0.01 to 2 g/l, preferably from 0.2 to 0.6 g/l and has a pH of 2 to 7. Reducing means can be arranged to regenerate the trivalent titanium in the treatment solution continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a phosphate treated metal surface.
sm4talliquea phoaphatAes
), or more precisely [post-processing (post -t
The present invention relates to a composition and a method for the treatment of paints, with particular application in post-treatment when such surfaces have to be subsequently coated with a paint layer.

The invention also relates to a process for making a composition as described above and to a concentrate that can be used in this process.

Phosphate coatings can be applied to the metal surfaces in question, particularly in the case of iron and zinc, as well as to iron, steel, zinc, metals, aluminum, and alloys of these metals. This is done for the purpose of imaging the surface of the substrate from corrosion. These surfaces may optionally be coated with a paint layer after the coating. The paints may in particular be based on lacquers, varnishes and enamels and are applied by, for example, dipping, electrophoresis, gun spraying or any number of other methods.

If treatment lines are already present on phosphate-coated metal surfaces, they are usually treated with a passivation cleaning.
ant) or post-treatment cleaning (rinqage d@poa
t-traitem@nt).

These treatments are carried out to further improve the corrosion protection of metal surfaces that have been previously treated with phosphate.
Trivalent and/or hexavalent chromium ions are generally used in the form of chromate-based chromating compositions or solutions used in the final or passivation cleaning.

Although such treatments provide sufficient protection against corrosion, they have two major drawbacks. most 11
A major drawback is that the chromating solution used and the residue, which requires treatment to remove excess ions, are highly toxic due to trivalent and hexavalent chromium ions. The second major drawback is that the degree of coloration is high, so if the paint layer applied after use is thin, the yellow spots will appear floating.

Various treatment methods based on chromium-free compositions have been attempted to replace this chromate treatment.

Among the methods proposed so far, for example, there is a treatment method in which the following composition is mainly applied to a surface that has been previously treated with phosphate.

- compositions comprising soluble salts of urconium; - compositions comprising fluorine-containing salts of calcium, zinc, aluminum; tetravalent titanium, zirconium, nickel; potassium monofluorotitanate or ammonium fluorotitanate forms; or a composition comprising tetravalent titanium in the form of potassium oxalate and titanyl oxalate.

Although these treatments have removed the drawbacks inherent in compositions caused by and containing chromium ions, they have not always been a sufficient solution. This is because the anti-corrosion protection provided by these methods to treated surfaces is similar to that for chromating (
This is because it was clearly inferior to the case where a chromating) composition was used.

In particular, the present invention provides a method for treating phosphated metal surfaces which provides the same protective effect on the surface as the prior art treatments using chromating solutions and which does not have the disadvantages mentioned above. and a composition thereof.

However, Applicant's ``j. This was an unexpected discovery, as the prior art treatment methods using tetravalent titanium were unsatisfactory from the point of view of the protective effect, and were awarded the award. This is a discovery worthy of praise.

For the following reasons, it is important to note that the treatment composition of the present invention contains a trivalent titanium compound in an effective proportion and exhibits an acidic pH! Let it be jwI. Needless to say, [proportion efficiency]
The expression J refers to the proportion of compounds such that the corresponding composition imparts a protective effect on treated metal surfaces equivalent to that obtained using known chromate treatment solutions.

More particularly, the compositions of the invention have a
It contains trivalent titanium in a concentration of 1, preferably 0.2 to 0.6 #/l, and has a pH of 2 to 7.

More particularly, the composition may contain, for example, about io to 5011
It is in the form of a concentrate which may contain up to /. of trivalent titanium.

This concentrate is desirably shielded from atmospheric oxygen until the moment of use, at which time it is diluted, preferably with distilled or deionized water. The amount of water is selected so that the trivalent titanium concentration in the final composition reaches an effective value.

, the treatment method of the present invention involves treating the phosphate-treated metal surface by contacting it with the composition of the present invention during the phosphate coating process, before applying a paint layer. It is characterized by The contact time must be long enough to impart the desired corrosion protection effect to the treated surface.

More particularly, this treatment method is carried out by hydrostatically or kinetically immersing the metal surface to be treated in the composition of the invention. The soaking time is between 10 and 60 seconds, and the temperature of the composition is below 90°C, preferably between 18 and 60°C.

Because trivalent titanium easily oxidizes to tetravalent titanium, compounds containing such trivalent titanium tend to have low stability, especially when in dilute solutions and when exposed to atmospheric oxygen. is relatively small. The compositions of the invention are therefore prepared during normal use and, if necessary, regenerated during operation by reducing the tetravalent titanium formed to trivalent titanium.

Accordingly, - according to a particular embodiment, the method for preparing the composition of the invention comprises reducing trivalent titanium by contacting the tetravalent titanium with a reducing means prior to applying the composition to a phosphated metal surface. During the treatment of the in-situ prepared and then phosphatized surface, a portion of the titanium composition is brought into contact with said reducing means to increase the concentration of the trivalent titanium compound in an effective proportion, particularly as described above. It is characterized by regenerating the trivalent titanium of the insect composition by maintaining the ratio such that trivalent titanium is contained in the range of 90.2 to 0.6.9.

According to another aspect, the above-described method for preparing the composition of the invention uses the concentrate of the invention and that the trivalent titanium concentration of the composition thus obtained is such that the trivalent titanium concentration is increased during operation. It is characterized in that it is maintained at its effective value by regeneration by contact with means for reducing it to titanium.

The aforementioned reproduction may be performed continuously.

The invention will be better understood from the supplementary description and examples given below with respect to advantageous implementations.

Assuming the treatment of phosphatized metal surfaces, which are optionally subsequently coated with one or more paint layers, in order to improve their resistance to corrosion, the following method or an equivalent method may be used: Perform the work according to the following.

First, the aforementioned metal surfaces, which may be the surfaces of metal substrates based on iron, steel, zinc, plated iron, plated steel, aluminum, alloys of these metals, cadmium, etc., are first prepared in a known manner. Subject to phosphate coating treatment. This process is primarily a degreasing process using alkaline lye and involves the action of a conventional phosphating acidic composition on the iron or zinc, which is usually carried out by hot working.
It is carried out for several minutes by dipping or spraying.

The metal surface is then treated with the composition of the invention, in particular after successive cleaning with tap water and deionized water.

The composition contains the trivalent titanium compound at an effective concentration, particularly 0.0
It contains 1 to 2 g/l, preferably 0.2 to 0.69 g/l, and has an acidic pH. The value of p■( is 2 to 7, preferably 2 to 5.

The trivalent titanium content of 0.2 to 0.6 El/l is 1
4,17 x 10 to 1,25 x 1
0-” Indicates that trivalent titanium with a Durham atom is included.

The pH may be adjusted with soda, ammonia, hydrofluoric acid, nitric acid, and various other acids or bases.

The composition is used at temperatures below 90°C, especially in the range from 18 to 60°C.

This treatment is preferably carried out by dipping the metal surface into the composition, usually for 10 to 60 seconds.

The composition may also be deposited by spraying, but this technique is disadvantageous compared to the previously described methods due to the susceptibility of trivalent titanium to oxidation.

After treatment, the metal surfaces are washed with water and dried, especially with heat, after which, if necessary, a paint layer is applied. The paint may be selected from paints, varnishes, enamels, etc., and may be applied in any suitable manner.

Cleaning as described above before applying the paint reduces the risk of air bubbles forming in the paint.

The given anti-corrosion protection against eel was determined by the salt-containing fog test (1'e
aaai au brouillard aalin
) can be tested. This test is American standard AST
MB 117 and ASTM D 1654-61, a detailed explanation will be given in their examples.

The mowing corrosion resistance rating given ranges from 0 (zero resistance) to 10.
It is divided into stages up to (extremely excellent resistance).

Trivalent titanium compounds include titanium chloride (trivalent) and bromide (trivalent)
Titanium, titanium fluoride (trivalent), titanium oxalate (trivalent),
and (trivalent) titanium sulfate. These compounds have been found to be particularly active.

(Hereinafter in the margins) It is advantageous if the compositions of the invention are initially prepared as concentrates. This concentrate may be, for example, about 10 to 50 I/7! may contain trivalent titanium.

Such concentrates can be diluted with a suitable amount of water, preferably water that has been deionized to avoid the introduction of contaminants such as magnesium and calcium, to form compositions of the invention. In addition to titanium, it also contains other ingredients that may be included in the composition. These components include, in particular: - small amounts, specifically about 0.001 to 0.02 J/
surfactants, especially sodium alkylsulfonates or ethoxylated hydrocarbons
organic surfactants such as ethoxyles), and-
A small amount of stabilizer, for example about 1 to 500 m/m,
In particular, pyrogallol or hydroquinone may be mentioned.

Since trivalent titanium is sensitive to atmospheric oxygen, the aforementioned concentrates are shielded from air until the moment of use.

This sensitivity of trivalent titanium also creates the need to regenerate the compositions of the present invention in order to maintain their trivalent titanium concentrations at effective values. This regeneration can be carried out by contact with reducing means, especially reducing agents.

When actually performing the treatment, it is preferable to equip the treatment container containing the composition with a branch pipe in which a reducing agent is placed.

If the treatment by immersion is of the hydrostatic type, the composition may be collected at the bottom of the vessel and reintroduced to the surface of the bath forming the hindlimb composition passed through a nine-branched tube containing the reducing agent.

If this immersion treatment is of the kinetic type, in which the component with the phosphatized surface to be treated is moved in translation, the direction of flow that occurs in the composition as a result of its introduction into the branch pipe is It may be advantageous to consider counter to the direction of translation of the member.

The reducing means may be a metallic or chemical reducing agent placed in the column or an electrolytic cell, in which case the composition to be regenerated into these columns or cells is such that the trivalent titanium concentration is maintained at an effective value. Flow something continuously or intermittently.

The oxidation and/or regeneration effects of the bath can be measured using a simple redox capacity measurement (dosage volumetric ox
regeneration is started or stopped so that the proportion of trivalent titanium in the composition remains within the aforementioned limits.

As the reducing agent, the following can be used. In the case of a metal reducing agent, one composed of zinc amalgam solid, one composed of cadmium particles, and one composed of Raney metals.

The reduction is preferably carried out in a medium consisting of hydrochloric acid or sulfuric acid (0.5 to 2N).

For one chemical reducing agent, N a B H4, K B
H4-NtxH:LPOz+fo:r;-Hz Composed of an alkali metal borohydride or an alkali metal hypophosphite salt, such as O.

These reducing agents are used hot and are characterized by the presence of a catalyst, especially potassium fluorotitanate (K, TIF,) -I
'Used when reducing to 1F-4.

If reduction is carried out electrolytically, inert electrodes are used and redox batteries (batteries redox) are used.
Follow the method used in

In view of the above description, it may be advantageous for the user to have at the same time a treatment composition and a reducing means for regenerating and possibly also producing the composition.

Accordingly, the invention provides, on the one hand, to have the composition of the invention in the form of a concentrate in which titanium is present, preferably in the trivalent state, and on the other hand to convert the composition prepared from the concentrate into a mixture of titanium from tetravalent titanium to trivalent titanium. an industrial product having reducing means (suitable for regeneration by reduction to titanium) and, if necessary, also used in a first step to bring the trivalent titanium concentration of the composition to the desired value. . This adjustment of the trivalent titanium concentration is necessary when the concentrate as the starting material is based on tetravalent titanium or when the content of trivalent titanium is too low.

Preferred embodiments of the present invention will be described below, and the advantages of the present invention will be clearly understood when the results of these embodiments are taken together.

Example 1 Fifteen specimens made of "standard quality steel plates formed by cold rolling" and having a thickness of s/low and a size of 150 a + x 70 m are carefully degreased using trichlorethylene and acetone sequentially. The specimens are then subjected to a phosphate coating by immersion.

For this treatment, a commercially available phosphating composition is used, in particular the composition known under the symbol 19-19-49 J-, at a concentration of 3% by weight.

The composition includes: a phosphatizing agent and a surfactant.

The pH is 4.8 to 4.9 and the operating temperature is 60C.

The test piece is immersed in the phosphate treatment composition for 10 minutes.

The resulting coating is an iron phosphate coating and the weight of the layer is 0.
2 to o, a, p,',,''.

The 15 test pieces whose surfaces were treated with phosphate in this manner were divided into three equal parts, each group containing five test pieces.

The first group, that is, group 11, was not subjected to any treatment to improve its anti-corrosion protection effect, and 2
Only wash it once in a row.

- Cleaning with tap water: Time = lO seconds Immersion temperature Two room temperatures - 120 - Theory Cleaning with ion-treated water: Time: 30 seconds Immersion temperature; room temperature The second group, i.e., group (2), is treated with chromate. Put it on. The procedure is as follows: Cleaning with tap water: Duration 810 seconds Immersion temperature: Room temperature - Final cleaning in chromium salt solution with pH equal to 3.4.

This solution was prepared with deionized water and had a 0.259
It contains 71 hexavalent chromium and 0.06 #/j trivalent chromium.

Time: 30 seconds Immersion temperature: Room temperature Washing with ion-treated water: Time: 5 seconds Immersion temperature: Room temperature The third group, group (3), was subjected to the treatment of the present invention in the following procedure.

Cleaning with tap water: Time: 10 seconds Immersion temperature: Room temperature One theory: It is prepared with ion-treated water, contains 0.331/L of trivalent titanium, and has a pH adjusted to 3.4 with soda. Final cleaning in titanium chloride (trivalent) solution: Time = 30 seconds Immersion temperature: Room temperature - Cleaning with deionized water pressure: Time: 5 seconds Immersion temperature: Room temperature 15 specimens treated in this way Dry for 5 minutes in a 150c dryer, then soak in water-soluble paint (paint marked with BOUVET, reference: Primai
A 6 noir aatlne (glossy black) A63 04 44) is applied taking into account the following conditions specified by the manufacturer.

Monoviscosity: 25 to 30 seconds, measured with a base 4 Ford cup, -pH: 8.8 to 9.2, - draining) time: 10 minutes, 1 Heating time and temperature = 160C for 15 minutes.

Three further sets of 15 specimens are processed under the same conditions.

These specimens are then subjected to a corrosion test with a 5% salt mist at a temperature of 35C according to the conditions specified in standard ASTM B 117. After 96 hours of exposure to this salt-containing fog, the results are confirmed according to standard ASTM D 1654-61.

The results obtained are shown in Table I below.

These values are the average of a series of three tests performed using three sets of 15 specimens.

Table 1 The above results show that specimens treated with trivalent titanium-based compositions have dog corrosion resistance comparable to that of conventional chromate treatments. Titanium chloride (
These results are noteworthy since the presence of chloride ions caused by 1) is known to have an adverse effect on corrosion resistance in baths of this type.

Example 2 Twenty-five specimens made of standard quality steel plate formed by cold rolling and having a thickness of 8/10yo+ and a size of 150 m x 70 mm are used.

These specimens are first carefully degreased with trichlorethylene and then with acetone and then subjected to a phosphating treatment by immersion.

This treatment is carried out using the same phosphate treatment composition and under the same conditions as in Example 1.

The resulting coating is an iron phosphate coating υ, and the weight of the layer is 0.
It is 2 to 0.3 W/i.

These test pieces were divided into five equal parts, each group containing five test pieces, and each group was subjected to the following treatment.

Group (1) Washing with knee tap water; Time: 10 seconds Immersion temperature: Room temperature - Washing with deionized water: Time: 30 seconds Immersion temperature: 60°C Group (2) Washing with knee tap water: Time : 10 seconds Immersion Temperature: Room temperature One theory: pH 3, prepared with ion-treated water and containing 0.25 g/'6 hexavalent chromium and 0.06 fA trivalent chromium.
Chromate treatment with chromium salt solution in step 4: Time: 30 seconds Immersion temperature: 60°C Cleaning with ion-treated water: Time: 5 seconds Immersion temperature: Room temperature Group (3) Cleaning with tap water: Time: 10 Soaking temperature: Room temperature One theory: Contains potassium fluorotitanate (or tetravalent titanium of about 12A) with ion treatment (prepared with 7% water, 59/I) and whose pH is adjusted to 4.5 with soda. Treatment by final cleaning with potassium fluorotitanate solution: Time: 30 seconds Immersion temperature = 60°C Ion treatment and cleaning with good wood; Time: 5 seconds Immersion temperature: Room temperature Group (4) Cleaning with knee tap water: Time: 10 seconds Immersion temperature: room temperature One theory: Prepared with ionized water, 51. / β of tetravalent titanium and i o y7a of sodium hypophosphite, potassium fluorotitanate and hypophosphite (pH adjusted to 4.5 with soda) in solution with IJium. Final cleaning treatment: Time: 30 seconds Immersion temperature: 60°C Cleaning with mono-deionized water: Time: 5 seconds Immersion temperature: Room temperature Group (5) Cleaning with knee tap water: Time: 10 seconds Immersion temperature: Room temperature Treatment of the invention with a final wash with a titanium fluoride (trivalent) solution containing -0.3 fA trivalent titanium.

This solution consists of 5f potassium fluorotitanate and 1(l) sodium hypophosphite (N a H4F Ox, H2O
) in deionized water 1-e, the mixture is heated to 60° C. and circulated in a closed circuit using a diaphragm pump over a column containing 30 t of powdered zinc. Manufactured by Yoshishi.

When the circulation flow rate is maintained at f0.7-87, it becomes 0.0 after 1 hour.
A pH 4.5 solution containing 3f/# of trivalent titanium is obtained. This solution can be used as is.

(A schematic diagram of the equipment used is shown in FIG. 1, and a trivalent titanium formation curve is shown in FIG. 2).

The apparatus shown in FIG. 1 comprises: - a container l filled with a composition 1b constituting a bath for sanitizing, in which a heating means such as a heating resistor 1a is disposed; A means for reducing tetravalent titanium to trivalent titanium, in which a metallic reducing agent R is disposed inside a column 2 positioned above a support 3, and a container 1 via a pipe 5. and the top of column 2 via tube 6t.
a pump 4 configured to collect a portion of b and pass it into column 2;

The curve in Figure 2 shows the change in Ti (m) content (in V) of the bath of composition 11 as a function of the time (in minutes) T (abscissa axis) during which recycle is maintained under the conditions described above. ordinate axis).

The treatment in this solution is carried out as follows.

Time: Soak for 30 seconds Temperature: 60℃ It is then washed with deionized water.

Time: 5 seconds Immersion Temperature: Room temperature The test piece thus treated was dried in a dryer at 150°C for 5 minutes, and then immersed in the water-soluble paint used in Example 1. Deposit by considering the conditions described.

35 according to the conditions of standard ASTM B 117.
All corrosion tests of these specimens are carried out with a 5-hour saline fog at a temperature of 5°C. After 96 hours of exposure to this salt-containing fog, the results are examined according to standard ASTM D 1654-61.

The results obtained are shown in Table n below. These values are 25
is the average value of the results of tests performed on three sets of individual specimens.

Table ■ The results in this table show that if the composition contains enough trivalent titanium, the corrosion resistance is comparable to that of conventional chromate cleaning treatments.

Example 3 Test specimens 8/10 m thick, 150 x 70 sieve, made of [standard quality steel plate formed by cold rolling] were divided into 3 groups of 5 each and sequentially treated with trichlorethylene and acetone. After carefully degreasing, process as described below.

monoalkaline degreasing compositions, especially commercially available rRidoli
Degreasing by spraying with ne910''i; Usage concentration: 1 layer tchi Usage temperature: 60°C Processing time: 90 seconds Usage pressure Crab 1.5) Cleaning with tap water: Time: 10 seconds Immersion temperature; Room temperature-IJ phosphate treatment solutions, especially the commercially available “Granodi
Phosphate conversion treatment by spraying using ``NE16'': Working temperature: 55° C. Spraying time: 1 minute Pressure: 0.8 pearls The result is a zinc phosphate coating with a layer weight of 12 to 3 qm.

Next, group 3 of 5 specimens [--each treated similarly to the 3 groups of specimens of Example 1.

After drying and application of water-soluble paint under the conditions of Example 10, these three groups of specimens were tested according to the standard ASTM B
117. 384 for salt-containing fog
The results are examined according to standard ASTM 1664-61 after time exposure. The results obtained are shown in Table ■ below.

These values represent the average of the results of three tests, ie, nine tests performed on three sets of three groups of five specimens.

Table Ill These results prove the validity of the nine conclusions obtained in Example 1.

Example 4 In this example, a steel sheet made of standard quality cold-rolled steel plate (1), thickness (2) 8710 m, size 15
A 0x70m test piece is used.

These test specimens were combined with [chlorethylene, then ゛1'
After carefully degreasing it for seven tons, it is subjected to the following treatment.

- Spray degreasing under the conditions of Example 3 using an alkaline degreasing composition, - Washing with tap water: Time: 10 seconds. Immersion temperature: Room temperature - Phosphation conversion by spraying under the conditions of Example 3. process.

These treatments result in zinc phosphate coatings having a layer weight of 2 to 39/i.

Three sets of five groups of five specimens are processed under Example 20 conditions.

All specimens are subjected to salt fog test (Standard ASTM
B117). Results are examined using data from standard ASTM D 1fi54-61 after 384 hours of exposure to this salt-containing fog. The obtained results are shown in Table 1v of F in 1.

These values are the average of test results obtained on three sets of specimens.

Table IV These results confirm the validity of the conclusions obtained in Example 2.

Thus, regardless of the method of implementation, a composition and method for treating phosphoric acid coated metal surfaces is achieved which has the features and advantages that will be clearly understood from the foregoing description.

Although it is a matter of course, as is clear from the explanation in Section F, the present invention is not limited to the specific embodiments described above,
On the contrary, it includes various modifications within its scope.

It is a figure which shows the titanium formation curve at.

1...Bath, 2...Column, R...R source agent, 4...
・Pump, 5, 6...pipe.

Representative Patent Attorney Moto Imamura.

Claims (9)

[Claims] (1) Phosphate coating is a composition for treating metal surfaces, characterized by containing an effective proportion of a trivalent titanium compound, and p) being acidic. composition. (2) 0.01 to 21/l, preferably 0.2 to Q
The composition according to claim 1, characterized in that it contains trivalent titanium in a concentration of .611/l and has a pH of 2 to 7. (3) A concentrate used after dilution with water to form a composition according to claim 1 or claim 2. (4) The concentrate according to claim 3, characterized in that it contains 10 to 501/l of trivalent titanium. (5) The concentrate according to claim 3 or 4, characterized in that it contains at least one type of surfactant and at least one type of stabilizer. (6)-Organic surfactants such as sodium alkyl sulfonates or ethoxylated hydrocarbons 0.001 to 0.0
Concentrate according to any one of claims 3 to 5, characterized in that it contains 1 to 500 mg/l of a stabilizer such as pyrogallol or hydroquinone. (7) Phosphate coating is a method for treating metal surfaces, optionally before applying a paint layer.
The phosphate-treated metal surface is defined in claim 1 or 2.
A method of treatment, characterized in that the contact time is long enough to impart the desired septic resistance to the treated surface. (8) The treatment method according to claim 7, which comprises immersing the surface to be treated in the composition according to claim 1 or 2. (9) Process according to claim 8, characterized in that the immersion time is 10 to 60 seconds and the temperature of the composition is lower than 90°C, preferably 18 to 60°C. α1 Claim 1 or 2 used in the processing method according to any one of Claims 7 to 9
A method for preparing a composition according to paragraph 1, in which trivalent titanium is formed in situ prior to depositing the composition on a phosphate-coated metal surface by contacting tetravalent titanium with a reducing means; In particular, a portion of the composition is treated with said reducing means so that the concentration of trivalent titanium compound in the composition is maintained in an effective ratio, in particular such that the concentration of trivalent titanium in the composition is between 0.2 and 6 fl/l of trivalent titanium. A process characterized in that the trivalent titanium of the composition is regenerated during treatment of a silinate-treated surface by contacting. 0υ Claim 1 or 2 used in the treatment method according to any one of Claims 7 to 9
In the method for producing the composition described in Claims 3 to 6, the concentrate according to any one of Claims 3 to 6 is diluted, and the trivalent titanium concentration of the composition thus obtained is , a manufacturing method characterized in that during treatment, the S value is maintained by a regeneration method in which tetravalent titanium is brought into contact with a means for reducing it to trivalent titanium. (121The means of reducing tetravalent titanium to trivalent titanium is -
The method according to claim 10 or 11□, characterized in that it is a metallic or chemical reducing agent arranged in a column or a monoelectrolytic cell. αj On the one hand, it has a 1# condensate according to any one of claims 3 to 6, and on the other hand, the composition formed from the concentrate is converted from tetravalent titanium to trivalent titanium. If the content of trivalent titanium in the starting material concentrate is too low, the reducing means may optionally reduce the trivalent titanium ( L - An industrial product which is characterized by also performing a function that brings about the desired value in the first stage.